r - 将两列绘制为条形图，将第三列绘制为折线图 ggplot

Question

我的 df 看起来像这样:

df <- data.frame(date = c('2016-01-01', '2017-01-01', '2018-01-01', '2019-01-01'),
                 "alo" = c(10, 11, 12.5, 9),
                 "bor" = c(18, 20, 23, 19),
                 "car" = c(100, 125, 110, 102)) %>%
  gather(-date, key = "key", value = "value")

我想将 alo 和 bor 列绘制为同一图上的两个条形图，因此我收集了 df。但是，我希望汽车列作为折线图而不是同一图表上的条形图。

目前，我的绘图代码是:

ggplot(df, aes(date, value, fill = key)) +
           geom_bar(stat = 'identity', position = "dodge")

请告知如何为第三列添加折线图而不是条形图。谢谢!

Answer 1

仅收集您想要在条形图中显示的列:

df <- data.frame(date = c('2016-01-01', '2017-01-01', '2018-01-01', '2019-01-01'),
                 "alo" = c(10, 11, 12.5, 9),
                 "bor" = c(18, 20, 23, 19),
                 "car" = c(100, 125, 110, 102)) %>%
  gather(alo, bor, key = "key", value = "value")

ggplot(df, aes(date)) +
  geom_col(aes(y = value, fill = key), position = "dodge") +
  geom_line(aes(y = car, group = 1))

如果你想在图例中使用 car 标签，做一些小技巧:

ggplot(df, aes(date)) +
  geom_col(aes(y = value, fill = key), position = "dodge") +
  geom_line(aes(y = car, group = 1, col = 'car')) +
  scale_color_manual(values = 'black') +
  labs(color = NULL, fill = NULL)